German Patent Publication DE 876,527 (Mailander), published on Sep. 4, 1952 discloses a method and apparatus for aligning sheet metal plates and cardboard panels or the like in lacquer-applying machines or printing machines. The articles to be aligned first are caused to travel along an alignment path with a speed which is larger than the speed of two stop members which extend crosswise to the feed advance direction and at a spacing from each other. The articles are pushed against these stop members.
As soon as the article abuts against one or both stop members, the article is aligned relative to the position of the stop members and the speed of the article is reduced to that of the stop members. Thus, the articles are brought into an exact position and their movement is synchronized with the work sequence of the machine in which the article is further treated for example by finishing steps. The stop members that travel along precise positions and in synchronism with the machine for further treatment are advanced in the known apparatus with chain drives, the upper run of which is located in the same plane in which transport chains for the article to be aligned travel. The transport chain entraining elements grip the articles at their rear end and run faster than the chains carrying the stop members, thereby pushing the articles against the stop members. The known apparatus and its components are so arranged for mutual cooperation that the articles to be aligned bear against or abut against the stop members before the articles are transferred to the machine for further treatment or finishing steps.
German Patent Publication 1,761,435 (Fischer et al.), published on Oct. 1, 1970 relates to a method and apparatus for the fitted alignment and supply of flat articles such as sheets of paper to machines that further process these sheets. The arrangement and construction is basically the same as in the above-described German Patent Publication 876,527, however, with the exception that in the device of Fischer et al. the flat sheets which are to be aligned in a fitted manner, overlap each other in the manner of fish scales which are transported to the input of a sheet processing machine such as a printer. The spacing from one leading edge to the next leading edge of the overlapping sheets is larger than the distance between stop members travelling in the transport direction. These stop members travel also in synchronism of the further processing machines so that each sheet is pushed by its faster running feeding device against stop members for alignment by the stop members and for application of a brake force by the stop members to the sheets. The sheets prior to reaching the stop members, rest on a transport belt where the sheets are held in place by gravity and by the overlapping in a fish scale manner, whereby a certain press down force is maintained. Following the sheet alignment, the sheets are taken over by the further processing machine or are fed into this machine sheet-by-sheet in single sheet feeding fashion.
German Patent Publication DE 4,114,479 (Greive), published on Dec. 17, 1992 discloses a method and apparatus for feeding, aligning, and holding of sheets for sheet processing machines such as the printing section of an offset sheet printing machine. Here again the method described above is basically employed in that sheets or articles to be aligned are caused to bear against brake force applying stop members so that the sheets assume the desired aligned position in response to a pushing force.
U.S. Pat. No. 3,199,864 (Irvine), issued on Aug. 10, 1965 discloses a document handling device for synchronizing the movement of a plurality of documents so that a predetermined spaced relationship exists between successive documents. Irvine is not concerned with properly aligning articles relative to an aligned position. Irvine is also not concerned with timing or synchronizing the document feeding with an operational sequence of another machine. Irvine discloses a rotating entraining member and a bow-shaped guide track partially surrounding the rotating entraining member. A plurality of guide rollers are so arranged that they can reach partially through respective openings in the guide track. The articles are supplied to the apparatus by a transport mechanism feeding the articles tangentially to the entraining member so that the articles enter into a gap between the rotating entraining member and the guide track or rather the guide rollers. A stop member rotating in the same direction as the rotating entraining member is arranged for a cooperation with the entraining member. The rotating stop member rotates somewhat slower than the entraining member which thus accelerates the articles until they are pushed against the entraining member. The entraining member itself is constructed as a rotating lever or as a rotating roller. The arrangements of components is such that the articles exit from the apparatus with uniform spacings between neighboring articles in a row. The apparatus is not suitable for an exact alignment of an article relative to a stop member or stop members because the articles can bear simultaneously against the entraining member and against two or more guide rollers so that the articles are not actually freely movable. Such a free movement, however, is necessary for the positional and timely alignment of the articles relative to an operational sequence of a further processing machine.
German Patent Publication DE 2,650,438 C2 (Irvine et al.), published on Jun. 16, 1977, discloses an apparatus for individually feeding single sheets from a stack. The sheets may have different thicknesses and several separator stations are arranged in a row.